Ore mill



June 26, 1951 B, J, PUGH 2,558,156

ORE MILL Filed Nov. 25, 1947 2 sheets-Sheet 1 June 26, 1951 B. J. PUGH2,558,156

ORE MILL Filed Nov. 25, 1947 2 Sheets-Sheet 2 Patented June 26, 1951STATES PATsT oFFlcE;

3 Claims` The present invention relates to an improved mill for reducingores containing precious metals, and more particularly to a millespecially adapted for use in reclaiming precious metals from piles ofrefuse ore which have previously been worked but in which a certainpercentage of the precious metal is still present.

At the present time, a great quantity of precious metal is wasted. Suchmetal is to be found. in piles of refuse which are present at the mine.In the original mining operation it is impossible to reclaim all of themetal present in the ore. Obtainment of this residue metal has been madediflicult due to an inadequate milling operation. The amount of preciousmetal in the refuse material does not justify the expense of hauling thematerial to an established mill. However, there is enough of thisprecious metal in the refuse material to justify its removal, providedthe cost of the operation is not too excessive. So far as s known, thereare no mills of a portable nature which are capable of being carried tothe mine and set up for operation.

The present invention has been designed so that it is suiiciently lightin weight in order that all parts may be easily carried to the site ofthe mine and can there be set up for operation, thereby making itpossible to reclaim any precious metal to be found in this waste orrefuse material at a minimum amount of expense.

The primary object of the invention, therefore, is to provide a grindingand crushing mill for reclaiming precious metals, the construction ofwhich permits it to be readily transported and erected at the mine or onthe site where the reclaiming is to be accomplished.

A further object of the inventionr is to provide improved means in theform of an amalgam pot for withdrawing the precious metal from the millso that tests can easily be made to determine the percentage of metal.being reclaimed from a given quantity of refuse material.

The above and other objects of the invention will in part be obvious,and will in part be hereinafter more fully pointed out.

In the drawings:

Figure 1 is a View partly in vertical section of the new and improvedmill;

Figure 2 is a top plan view thereof; and

Figure 3 is a top plan view of one of the grinding and crushingelements.

Referring to the drawings for a more detailed description thereof, thenew and. improved mill which is generally designated by the referencenumeral 5 is shown supported on a concrete base 6. As previouslyindicated, this mill is delivered in a disassembled condition to thesite of the mine, and is adapted to be erected on the site where therefuse material is to be found. The first step in erecting the mill isthe construction of the base 6. This base is built solidly enough tosupport the entire weight of the mill, and a cavity or recess I isformed therein for a purpose to be hereinafter more fully described.

The mill 5 includes an open framework comprising vertically extendingupright members 8 which may be of angle iron formation. These uprightmembers are united by means of spaced transverse members 9 and I0, whichmembers support the. driving mechanism for the grinding and crushingmembers.

The container for the refuse material to be reclaimed is a relativelylarge cylindrical-shaped drum II which is securely fastened to the base6 by means of tie rods I2. These tie rods are anchored at one end to thedrum I I as indicated at I3, while the other end thereof is securelylocked within the base 6 as indicated at I4. Asis to be understood, aseries of these tie rods are employed around the circumference of thedrum for holding said drum in locked position on the basa Any desiredmeans, not shown, may be employed fory delivering the refuse materialthrough the open end of the drum Il, and as is conventionally practiced,a stream of water isV fed into the drum to be mixed with the refusematerial. One means of feeding Water into the drum is shownv in Figure 1of the drawing, which includes a feed` pipe i5 having a control valve I6mounted in the line, said pipe terminating in the bottomV wall of thedrum, as indicated at I'I. Thus, a steady and regulated stream of Wateris fed into the drum II for mixture with the refuse material which isfed in from the upper end of said drum.

The mill 5 further includes a pair of grinding disks I8 and I9,respectively. The grinding disk I8 is fixedly mounted against rotationon the bottom wall 2S of the drum II by any desired means. The grindingdisk IS isv mounted for rotation relative to the grinding disk it, andthe meeting faces of said disks are tapered and beveled as indicated at2! to give a crushing eiiect t0v the refuse ore during the action of themill- In other words, as seen in Figure 3 of the drawingsZ tapered lands22 are formed on the meeting faces of the disks so that as the rotatinggrinding disk I9 is driven, it will ride up on the tapered and beveledface of the stationary grinding disk l-8. isV this action takes place,the refuse ore will move between the meeting faces of the disks and uponcontinued rotation of disk I9, will be ground and crushed between thefaces of said disks.

The means for rotating the disk I9 includes a fixed vertically extendinghollow shaft 23 and a second tubular shaft 24. The second shaft 24completely encases the major portion of the hollow shaft 23. The lowerend of the hollow shaft 23 is formed with a mutiplicity of spacedperforations 25, for a purpose to be hereinafter more fully described.The upper end of the shaft 23 is xedly held within the member I9. Arelatively large gear wheel 26 is mounted for rotation on the shaft 23,said gear wheel being slightly spaced above the member 9. Journalledbetween the members 9 and i0 and in mesh with the gear wheel 23, are apair of long pinions 21 and 28. The shaft of the pinion 28 is drivenfrom a gear 29 which is in mesh with a Worm 39 driven by a shaft 3|. Theshaft 3l may be driven by any desired means, there being illustrated apulley wheel 32 on which may be mounted a driving belt extending from amotor located at a remote point, and not shown in the drawing. Themechanism just described forms one means for imparting rotation to thegrinding disk I9, and at the same time permits said disk to movevertically on the tubular shaft 24.

The grinding disk I9 is mounted for rotation with the shaft 24. Themeans of connecting the grinding disk I9 to the shaft 24 comprises abracket 33 having a sleeve 35 secured to the shaft 24. The bracket 33further includes laterally extending arms 35 which are attached to thegrinding disk I9 by means of bolts 35. From this construction it will beseen that as the shaft 24 is rotated, it will carry with it the bracket33 and grinding disk I9. Of course, the upper end of the shaft 24carries a collar 31 which is attached by any desired means to the gearwheel 29 for rotation therewith.

By means of the construction previously described, the refuse ore orprecious metal-bearing mass is ground and crushed to a relatively finestate so that all precious metal contained therein will be released. Inaccordance with the present invention, a small quantity of mercury isdeposited within the drum II, and as the metal within the crushed ore isreleased, it will be attracted to the mercury and pass therewith throughthe perforations 25 in the lower end of the shaft 23. Thus, thisperforated end of the shaft 23 becomes in eiect an amalgam pot, and thecollection of metal and mercury will pass from the perforated end of theshaft downwardly into a collection tube 39. This collection tube 38 issuitably secured to the bottom wall of the drum II and is embeddedwithin the base 6. The lower end of the collection tube, however, isdisposed within the recessed portion 1 in the base. That area of thecollection tube which is disposed within the recess carries a shut-01Tvalve 39 of conventional construction, and a cap 49. The cap 40 isscrewed on the end of the pipe and is formed with a lever 4I tofacilitate removal and placement thereof. lf desired, additional bolts42 may be employed for locking the base of the drum II onto the concretebase 6. The heads of these bolts are accessible from the recess 1. Thesebolts may also serve to retain the collection pipe retaining flange andwasher which are designated by the reference numeral 43 in position.

It is thought that the operation of the ore mill is readily obvious fromthe above description when taken in connection with the accompanyingdrawing. A motor or other means is employed for driving the worm gear 39and its shaft 3 I, rotation of which drives the gear 29 and pinion 28.As the pinion 28 is rotated, it will in turn drive the meshed gear wheel2B and the other pinion 21. As the gear wheel 26 rotates, the shaft 24will likewise be rotated, carrying with it the grinding disk I9. As thegrinding disk I9 is rotated, it will rise and fall on the beveled andtapered face of the stationary grinding disk I8, and this continualrising and falling and rotary movement of the grinding disk will crushand grind the refuse ore material which is being lodged between thefaces of the grinding disks to a very line state. The refuse material isbeing constantly fed into the drumv II and mixes with the water which isadmitted into the drum through the feed pipe I5. As the refuse materialis crushed into a very ne state, the precious metal will be released andimmediately attracted to the mercury which is present within the drum.The mercury and the attracted metal will then now through theperforations 25 downwardly into the collection tube 38, the valve 39being open to allow for the collection of the freed metal. A

From time to time the operator of the mill may want to make a test todetermine the amount of precious metal which is being recovered from acertain quantity of refuse material which has been fed into the drum.This can readily be determined by rst closing the valve 39 and thenremoving the cap 9, thereby allowing the recovered metal to be depositedin a pan 44. By weighing the amount of recovered material in the pan 44,he can readily determine the approximate value of metals to be obtainedper ton from the pile of refuse ore. Also, from time to time the valve39 `will be closed and the cap removed for collection of the metal whichhas been recovered within the amalgam pot.

As the amalgam pct proper is between the valve 33 and cap 49, it takesabout thirty poundsof mercury to ll the amalgam pot and to extend partWay back on the disk so that the drop of the disk splashes the mercuryto all the lower parts of the mill, bringing it in contact with thefreed parts of precious metal.

It is obvious that many changes may be made in the details ofconstruction without departing from the spirit of the invention as setforth in the appended claims.

Having thus described my invention, what I claim as new and useful is:

l. In an ore grinding mill of the character described for recoveringprecious metals, a base, a frame detachably mounted on said base, an orereceiving drum supported in said frame and on said base, a grinding diskxedly mounted on the bottom of said drum, a hollow shaft risingcentrally of said disk and upwardly through said fram-e, the lower endof said shaft mounted within said disk being perforated, a second shaftfor vertical sliding movement surrounding said first mentioned verticalshaft and rotatable relative thereto, a second grinding disk rigidlyattached to said last named rotatable shaft in close proximity to saidstationary disk, a series of inclined portions formed on the meetingfaces of said grinding disks extending about angular distances ofapproximately 90 degrees, and means whereby said second grinding diskwill be rotated and reciprocated relative to said stationary disks theinclined portions on said grinding disks providing mutually engagingspiral grinding surfaces.

2. In an ore grinding mill of the character described for recoveringprecious metals, a base, a frame detachably mounted on said base, an orereceiving drum supported in said frame and on said base, a grinding diskiixedly mounted on the bottom of said drum, a hollow shaft risingcentrally of said disk and upwardly through said frame, the lower end ofsaid shaft being perforated, a second shaft surrounding said verticalshaft and mounted for rotatable and vertical sliding movement relativethereto, a Second grinding disk attached to said second rotatable shaftin close proximity to said stationary disk in series of spiral inclinedportions formed on the meeting faces of said grinding disks, acollection tube mounted in said base and in communication with saidperforated tube for receiving the recovered metal released from the oreby said disks, and means lwhereby said second grinding disk is rotatedand reciprocated relative to said stationary disk for grinding andcrushing the ore within the drum to separate the precious metaltherefrom said spiral portions forming mutually engaging grindingsurfaces extending an angular distance of at least 90 degrees.

3. The structure as set forth in claim 2, wherein means are providedWithin the base for recovering the metal received Within the collectiontube.

BENJAMIN J. PUGI-I.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS McKeever Sept. 26, 1939

